I have actually run a few LA's and FP's [good bushing engines made previous to LA's] with and without the baffle and it made a 300 to 400 rpm difference. I also reamed out the the exhaust pipe a few drill sizes and that added a few hundred more rpm, up to 600 rpm over stock on 15% omega. Yes it is louder but not that much over stock. I fly at two different wide open fields and the noise was not enough louder to draw any attention. It was enough power difference to notice on the planes I flew. No problem with tuning or fuel draw.
Fred